The present application and the prior applications referenced above are concerned with apparatus and methodology for aiding in portioning an item. This needs to be done for example in accurately portioning an irregularly shaped fish fillet or meat cut to a weight or price desired by a customer at the point of sale in a retail market.
In the apparatus and method described in the co-pending U.S. application Ser. No. 10/744,059, a sensor arrangement support is positioned above an item over a first reference section and then moved to a position over a second selected section, the portion between the two sections comprising a selected segment of the item. Various contour sensing arrangements and displacement detector devices are described to generate signals corresponding to the extent and direction of travel of the support in moving to the second section as well as to the cross sectional contours of sections of the item along the selected segment. From the signals of the displacement detector and contour sensor devices, the volume of any segment of the item is computed and a corresponding numeric value (weight or price) is displayed for viewing by the customer and the server. This provides a convenient way of displaying the weight or price of any segment of the item defined between any two sections of the item. The item can therefore be cut so as to provide any desired portioning of the item and this portion will be of an accurately known weight or price prior to being cut.
The aforementioned co-pending patent application describes a wide variety of contour sensor arrangements including an array of mechanical plungers or an inline series of non-contacting sensors, such as sonic or optical sensors.
Some of the various sensors described therein are relatively costly and/or not ideally suited to environments in which the apparatus is contemplated as being used, i.e., where contact of the apparatus with foods will inevitably occur, and where the equipment must be regularly cleaned thoroughly. Also, abuse of the equipment must be expected when unskilled personnel operate the same, particularly in a rushed atmosphere and delicate sensors might not be able to function well over a reasonable service life or need frequent repair or adjustment.
It is the object of the present invention to provide an apparatus and method of the above described type in which improved devices are used to determine displacements which are low in cost, rugged and reliable, and yet provides very accurate determination of the extent and direction of displacement of various components of the apparatus.